#compdef darcs

# EXTENDED_GLOB is required fr pattern backreferences.
setopt EXTENDED_GLOB

local DARCS=$words[1]

# test whether to hide short options from completion
autoload -z is-at-least
local hide_short
if zstyle -s ":completion:${curcontext}" hide-shortopts hide_short; then
  case $hide_short in
    true|yes|on|1) hide_short='!' ;;
    *) hide_short='' ;;
  esac
else
  is-at-least 4.1 || hide_short='!'
fi



_darcs_main() {
# Based on section 6.8 of _A User's Guide to the Z-Shell_ by Peter Stephenson.
# Also based on the tla completion module by Jason McCarty. How do I credit
# this?
local DARCS=$words[1]
local arguments
local curcontext="$curcontext"

if (( CURRENT > 2 )); then
    local cmd=${words[2]}
    local var_cmd=cmd_${cmd//-/_}
    curcontext="${curcontext%:*:*}:darcs-${cmd}:"
    (( CURRENT-- ))
    shift words

    local short long arg desc action
    short=()
    long=()
    arg=()
    desc=()
    action=()   
    arguments=()
    
    # Collect all help lines which have a leading space.
    local input
    input=(${(f)"$($DARCS $cmd -h)"})
    input=(${input:#[^\ ]*})
    local i
    for (( i=1 ; i <= ${#input} ; i++ )); do
	# Assumption: the the argument descriptions from `darcs cmd -h` 
	# have the following format:
	# [spaces]<-f>[spaces][--flag]<=<spaces>argument>[spaces][description]
	[[ "$input[i]" = (#b)' '#(-?|)' '#([^' ']#|)' '#(--[^=' ']#)(=([^' ']#)|)' '#(*) ]] \
		|| _message -e messages "cannot parse command help output." || return 1

	short[i]="$match[1]"
	long[i]="$match[3]"
	arg[i]="$match[5]"
	desc[i]="$match[6]"
	desc[i]="${${desc[i]//\[/\\[}//\]/\\]}" # escape brackets	

	case $arg[i] in
	DIRECTORY)
	  action[i]='_files -/' ;;
	FILE|FILENAME|IDFILE|KEYS)
	  action[i]='_files' ;;
	USERNAME)
	  action[i]='_users' ;;
	EMAIL|FROM)
	  action[i]='_email_addresses' ;;
	URL)
	  action[i]='_darcs_repository_or_tree' ;;
	*)
 	  action[i]='' ;;
 	esac
    done
    
    # Compute the exludes for _arguments

    local excluded short_excluded long_excluded k

    for (( i=1 ; i <= ${#input} ; i++ )); do
	excluded=()
	for opt (${=excludes[$long[i]]}); do
	    k=$long[(i)$opt]
	    excluded=($excluded $short[k] $long[k])
	done

	# Generate arguments for _arguments.
	# Make long and short options mutually exclusive.
	short_excluded=($long[i] $excluded)
	long_excluded=($short[i] $excluded)
	[ $short[i] ] && arguments=("$arguments[@]"
	    "${hide_short}(${short_excluded})${short[i]}[${desc[i]}]${arg[i]:+:$arg[i]:$action[i]}")
	[ $long[i] ] && arguments=("$arguments[@]"
	    "(${long_excluded})${long[i]}${arg[i]:+=}[${desc[i]}]${arg[i]:+:$arg[i]:$action[i]}")
    done

    arguments=("$arguments[@]" "${(@P)var_cmd-*:FILE:_files}")
else
    local hline
    local -a cmdlist
    _call_program help-commands darcs --help | while read -A hline; do
	(( ${#hline} < 2 )) && continue
	[[ $hline[1] == darcs ]] && continue
 	[[ $hline[1] == [A-Z]* ]] && continue
 	cmdlist=( $cmdlist "${hline[1]}:${hline[2,-1]/(#b)([A-Z])(*)./${match[1]:l}$match[2]}" )
     done
    arguments=(':commands:(($cmdlist))')
fi

_arguments -S -A '-*' \
    "$arguments[@]"
}



#
# Command argument definitions
#
local -a cmd_initialize cmd_get
cmd_initialize=()
cmd_get=(':repository:_files -/' ':new repository name:_files -/')

local -a cmd_add cmd_remove cmd_move cmd_replace
cmd_add=('*:new files:_darcs_new_file_or_tree')
cmd_remove=('*:existing controlled files:_darcs_controlled_files -e')
cmd_move=('*:existing controlled files:_darcs_controlled_files -e')
cmd_replace=(':old token:' ':new token:' '*:existing controlled files:_darcs_controlled_files -e')

local -a cmd_record cmd_pull cmd_push cmd_send cmd_apply
cmd_record=('*:controlled files:_darcs_controlled_files')
cmd_pull=(':repository:_darcs_repository_or_tree')
cmd_push=(':repository:_darcs_repository_or_tree')
cmd_send=(':repository:_darcs_repository_or_tree')
cmd_apply=(':patch file:_files')

local -a cmd_whatsnew cmd_changes
cmd_whatsnew=('*:controlled files:_darcs_controlled_files')
cmd_changes=('*:controlled files:_darcs_controlled_files')

local -a cmd_tag cmd_setpref cmd_check cmd_optimize
cmd_tag=()
cmd_setpref=(':preference key:(test predist boringfile binaries)' ':value:_files')
cmd_check=()
cmd_optimize=()

local -a cmd_amend_record cmd_rollback cmd_unrecord cmd_unpull cmd_revert cmd_unrevert
cmd_amend_record=('*:controlled files:_darcs_controlled_files')
cmd_rollback=()
cmd_unrecord=()
cmd_unpull=()
cmd_revert=('*:controlled files:_darcs_controlled_files')
cmd_unrevert=()

local -a cmd_diff cmd_annotate
cmd_diff=('*:controlled files:_darcs_controlled_files')
cmd_annotate=('*:controlled files:_darcs_controlled_files')

local -a cmd_resolve cmd_dist cmd_trackdown cmd_repair
cmd_resolve=()
cmd_dist=()
cmd_trackdown=(':initialization:' ':command:')
cmd_repair=()


#
# Completion functions
#

(( $+functions[_darcs_new_files] )) ||
_darcs_new_files () {
    local -a new_files
    local -a local_files
    local in_tree_head in_tree_tail
    _darcs_make_tree_path in_tree_head in_tree_tail || return 1
    new_files=(${(f)"$(cd $(_darcs_absolute_tree_root)/$in_tree_head; $DARCS whatsnew -sl .)"})  
    new_files=(${${new_files:#[^a]*}//a /})

    local_files=()
    for file ($new_files); do
	[[ $file:h = $in_tree_head && $file:t = ${in_tree_tail}* ]] && local_files+=$file:t
    done

    compset -P '*/'
    _description new_files expl "new files"
    compadd "$expl[@]" "$local_files[@]"
}




# _darcs_controlled_files [-e|r] [-f|d]
#
# Adds controlled files to the completion. Can take either
# -e or -r as flags which respectively only add the existing
# files or the deleted files. Can take either -f or -d which
# respectively add only the files or directories.
(( $+functions[_darcs_controlled_files] )) ||
_darcs_controlled_files() {
    local abs_root=$(_darcs_absolute_tree_root)
    local only_removed only_existing only_files only_dirs
    zparseopts -E \
	'r=only_removed' 'e=only_existing' \
	'f=only_files' 'd=only_dirs'

    local in_tree_head in_tree_tail
    _darcs_make_tree_path in_tree_head in_tree_tail
    local recorded_dir="$abs_root/_darcs/current/$in_tree_head"
    local -a controlled_files controlled_dirs existing_files existing_dirs 
    local -a dir_display_strs removed_dir_display_strs
    controlled_files=${(z)$(print $recorded_dir/$in_tree_tail*(.:t))}
    controlled_dirs=${(z)$(print $recorded_dir/$in_tree_tail*(/:t))}
    existing_files=() existing_dirs=()
    removed_files=() removed_dirs=() 
    dir_display_strs=() removed_dir_display_strs=()
    local dir file
    for dir ($controlled_dirs); do
	if [[ -e $abs_root/$in_tree_head/$dir ]]; then
	    existing_dirs+="$dir"
	    dir_display_strs+="$dir/"	
	else
	    removed_dirs+="$dir"
	    removed_dir_display_strs+="$dir/"
	fi
    done
    for file ($controlled_files); do
	if [[ -e $abs_root/$in_tree_head/$file ]]; then
	    existing_files+="$file"
	else
	    removed_files+="$file"
	fi
    done

    compset -P '*/'
    if (( ! ${#only_removed} )); then 
	_description controlled_files expl "existing revision controlled files"
	(( ! ${#only_dirs} )) && compadd "$expl[@]" $existing_files
	(( ! ${#only_files} )) \
	    && compadd "$expl[@]" -q -S / -d dir_display_strs -a -- existing_dirs
    fi
    if (( ! ${#only_existing} )); then
	_description removed_files expl "removed revision controlled files"
	(( ! ${#only_dirs} )) && compadd "$expl[@]" $removed_files
	(( ! ${#only_files} )) \
	    && compadd "$expl[@]" -q -S / -d removed_dir_display_strs -a -- removed_dirs
    fi
}

(( $+functions[_darcs_repositories] )) ||
_darcs_repositories() {
  local local_repos_path="$(_darcs_absolute_tree_root)/_darcs/prefs/repos"
  local global_repos_path="$HOME/.darcs/repos"
  local -a local_repos global_repos
  [[ -e $local_repos_path ]] && local_repos=( $(<$local_repos_path) )
  [[ -e $global_repos_path ]] && global_repos=( $(<$global_repos_path) )
  _description repositories expl "repositories"
  (( ${#local_repos} )) && compadd "$expl[@]" -- "$local_repos[@]"
  (( ${#global_repos} )) && compadd "$expl[@]" -- "$global_repos[@]"
}



# Combination completion functions

(( $+functions[_darcs_new_file_or_tree] )) ||
_darcs_new_file_or_tree() {
    local base_dir=$( cd ${$(_darcs_repodir):-.}; pwd -P)
    [[ -z $(_darcs_absolute_tree_root $base_dir) ]] && return 1
    local -a ignored_files
    ignored_files=(_darcs)
    _alternative 'newfiles:new file:_darcs_new_files' \
		 "directories:tree:_path_files -/ -W$base_dir -Fignored_files"
}

(( $+functions[_darcs_repository_or_tree] )) ||
_darcs_repository_or_tree() {
    local -a ignored_files
    ignored_files=(_darcs)
    _alternative 'repository:repository:_darcs_repositories' \
		 "directories:directories:_path_files -/ -Fignored_files"
}


#
# Mutually exclusive options 
#

typeset -A excludes
excludes=(
# Output
    --summary                     '--no-summary'
    --no-summary                  '--summary'
    --context                     '          --xml-output --human-readable --unified'
    --xml-output                  '--context              --human-readable --unified'
    --human-readable              '--context --xml-output                  --unified'
    --unified                     '--context --xml-output --human-readable          '

# Verbosity
    --verbose                     '          --quiet --standard-verbosity'
    --quiet                       '--verbose         --standard-verbosity'
    --standard-verbosity          '--verbose --quiet                     '

# Traversal
    --recursive                   '--not-recursive'
    --not-recursive               '--recursive'
    --look-for-adds               '--dont-look-for-adds'
    --dont-look-for-adds          '--look-for-adds'

# Pattern
    --from-match                  '             --from-patch --from-tag'
    --from-patch                  '--from-match              --from-tag'
    --from-tag                    '--from-patch --from-match           '
    --to-match                    '           --to-patch -to-tag'
    --to-patch                    '--to-match            -to-tag'
    --to-tag                      '--to-match --to-patch        '

# Repository Properties
    --plain-pristine-tree         '--no-pristine-tree'
    --no-pristine-tree            '--plain-pristine-tree'
    --parial                      '--complete'
    --complete                    '--partial'
    --compress                    '--dont-compress'
    --dont-compress               '--compress'
    --set-default                 '--no-set-default'
    --no-set-default              '--set-default'

# Logs
    --edit-long-comment           '--skip-long-comment --leave-test-directory'
    --skip-long-comment           '--edit-long-comment --leave-test-directory'
    --prompt-long-comment         '--edit-long-comment --skip-long-comment'

# Security
    --sign                        '       --sign-as --sign-ssl --dont-sign'
    --sign-as                     '--sign           --sign-ssl --dont-sign'
    --sign-ssl                    '--sign --sign-as            --dont-sign'
    --dont-sign                   '--sign --sign-as --sign-ssl            '
    --verify                      '         --verify-ssl --no-verify'
    --verify-ssl                  '--verify              --no-verify'
    --no-verify                   '--verify --verify-ssl            '
    --apply-as                    '--apply-as-myself'
    --apply-as-myself             '--apply-as'

# Conflicts
    --mark-conflicts              '--allow-conflicts --no-resolve-conflicts --dont-allow-conflicts'
    --allow-conflicts             '--mark-conflicts --no-resolve-conflicts --dont-allow-conflicts'
    --no-resolve-conflicts        '--mark-conflicts --allow-conflicts --dont-allow-conflicts'
    --dont-allow-conflicts        '--mark-conflicts --allow-conflicts --no-resolve-conflicts '

# Test
    --test                        '--no-test'
    --no-test                     '--test'
    --leave-test-directory        '--remove-test-directory'
    --remove-test-directory       '--leave-test-directory'

# Misc
    --force                       '--no-force'
    --no-force                    '--force'
    --ask-deps                    '--no-ask-deps'
    --no-ask-deps                 '--ask-deps'
    --date-trick                  '--no-date-trick'
    --no-date-trick               '--date-trick'
    --set-scripts-executable      '--dont-set-scripts-executable'
    --dont-set-scripts-executable '--set-scripts-executable'
)



#
# Utility functions
#

# _darcs_make_tree_path in_tree_head_name in_tree_tail_name path
# Set in_tree_head_name in_tree_tail_name to the corresponding path
# parts from inside the current darcs tree.
_darcs_make_tree_path () {
    [[ -z $3 || $3 = '.' ]] && 3=${PREFIX:-./}
    local _in_tree=$(_darcs_path_from_root ${$(_darcs_repodir):-.}/$3)
    [[ -z $_in_tree ]] && return 1
    4='' 5=''
    if [[ ${3[-1]} = / ]]; then 
	4=$_in_tree
    else
	4=$_in_tree:h
	[[ $_in_tree:t != . ]] && 5=$_in_tree:t
    fi
    set -A "$1" "$4"
    set -A "$2" "$5"
}

_darcs_repodir () {
    local index=$words[(i)--repodir*]
    if (( index < CURRENT )); then
	if [[ $words[$index] = --repodir ]]; then
	    (( index++ ))
	    print $words[$index]
	else
	    print ${words[$index]#*=}
	fi
    fi
}

_darcs_absolute_tree_root () {
    local root=$(_darcs_repodir)
    [[ -z $root ]] && root=$(pwd -P)
    while [[ ! $root -ef / ]]; do
	[[ -d $root/_darcs ]] && break
	root="$root/.."
    done
    [[ $root -ef / ]] || print $(cd $root; pwd -P)
}

_darcs_tree_root () {
    local abs=$(_darcs_absolute_tree_root)
    local rel=$(_darcs_relative_path $abs $(pwd -P))
    [[ -n $abs ]] && print $rel
}

# _darcs_paths_from_root name paths
# Sets name to the paths relative to the darcs tree root.
# If no argument is given then the current directory
# is assumed.
_darcs_paths_from_root () {
    local name=$1
    abs=$(_darcs_absolute_tree_root)
    [[ -z $abs ]] && set -A "$name" && return 1
    shift
    1=${1:=$PWD}
    local -a subpaths
    _darcs_filter_for_subpaths subpaths $abs $*
    local i
    for (( i=1; i<=${#subpaths}; i++ )); do
	[[ $subpaths[$i] != '.' ]] && subpaths[$i]="./$subpaths[$i]"
    done
    set -A "$name" "$subpaths[@]"
}

_darcs_path_from_root() {
    local path
    _darcs_paths_from_root path $1
    [[ -n $path ]] && print "$path"
}

# _darcs_filter_for_in_dir name dir paths
# Sets name to the relative paths from dir to the given paths which 
# traverse dir. It ignores paths which are not in dir.
_darcs_filter_for_subpaths () {
    local name=$1 dir=$2 
    shift 2
    local p rel
    local -a accepted_paths 
    accepted_paths=()
    for p; do
	rel=$(_darcs_path_difference $p $dir)
	[[ -n $rel ]] && accepted_paths+="$rel"
    done
    set -A "$name" "$accepted_paths[@]"
}

# _darcs_path_difference p1 p2
# Print the path from p2 to p1. If p2 is not an ancestor of p1 then it 
# prints a blank string. If they point to the same directory then it returns
# a single period. p2 needs to be a directory path.
_darcs_path_difference () {
    local diff=$(_darcs_relative_path $1 $2)
    [[ ${diff%%/*} != .. ]] && print $diff || return 1
}


# Print the a relative path from the second directory to the first,
# defaulting the second directory to $PWD if none is specified.
# Taken from the zsh mailing list.
_darcs_relative_path () {
    2=${2:=$PWD}
    [[ -d $2 && -d $1:h ]] || return 1
    [[ ! -d $1 ]] && 3=$1:t 1=$1:h
    1=$(cd $1; pwd -P)
    2=$(cd $2; pwd -P)
    [[ $1 -ef $2 ]] && print ${3:-.} && return

    local -a cur abs
    cur=(${(s:/:)2})        # Split 'current' directory into cur
    abs=(${(s:/:)1} $3)     # Split target directory into abs

    # Compute the length of the common prefix, or discover a subdiretory:
    integer i=1
    while [[ i -le $#abs && $abs[i] == $cur[i] ]]
    do
	((++i > $#cur)) && print ${(j:/:)abs[i,-1]} && return
    done

    2=${(j:/:)cur[i,-1]/*/..}       # Up to the common prefix directory and
    1=${(j:/:)abs[i,-1]}            # down to the target directory or file

    print $2${1:+/$1}
}

# Code to make sure _darcs is run when we load it
_darcs_main "$@"